Abstract: This paper presents an example of a malware attack on a virtual computer. Human factor and social engineering techniques are believed to play a major role in malware attacks. Insufficient education of the user regarding the information safety facilitates further action of the attacker. The attacker writes the malware code if necessary - as a key logger, downloader, etc. Every attack includes good preparation, port scanning, collecting information about antivirus software and target computer usage, considering the scenario of the attack, and choosing the best timing and method of the attack. The paper discusses anti-forensic role of Trojans in a corrupt virtual computer from which the abuse was committed, without the owner’s knowledge. Furthermore, the paper provides more information about the experimental verification of forensic activities aimed to prove the so called “Trojan Defense” in virtual environments.